Research

We are pleased to post this white paper from The HDF Group intern, Chen Wang. This paper looks at the steps of analyzing and tuning the HACC-IO benchmarks, the impact of different access patterns, stripe settings and HDF5 metadata. It also compares the five benchmarks on two different parallel file systems, Lustre and GPFS and shows that HDF5 with proper optimizations can catch up the pure MPI-IO implementations. An I/O Study of ECP Applications...

On February 6, 2020, the members of the ECP ExaIO project, Elena Pourmal and Scot Breitenfeld (The HDF Group), Quincey Koziol (NERSC), and Suren Byna (LBNL), presented HDF5 Tutorial at the ECP Annual Meeting. We've posted the slide deck and Q&A for your convenience....

Why do we use HDF5? We moved to HDF5 for our simulation data in 2016 from using our own proprietary file format. HDF5 had been on our radar for some time and we spent a couple of years investigating it and other file formats before deciding which we should switch to. HDF5 met all the criteria we had at the time. Amongst the criteria were: performance in speed and size, an accepted standard for scientific data, being open source, providing additional tools....

With MyIRE and HDF, everyone from a doctor in a small-town office to big data genetics researchers can work together to find new and powerful insights across data sets using a common set of tools - and do so in a repeatable way. And, because of HDF5, any user—whether large or small—is powered by the same technology used by CERN and NASA. We knew we wanted all of MyIRE’s users to have the power of NASA in their pocket. HDF5 made that possible....

The topic of software citation has been discussed in many forums recently and several major discovery repositories (e.g. zenodo and DataCite) support metadata for software in addition to datasets and other resource types. HDF5 stradles the boundary between the dataset and software worlds. It is most commonly thought of and referred to as a data format, but, as in any case, data written in the HDF formats can not be read without HDF software. So, the answer to the question: is it a format or is it software? is clearly both....

Tobias Weinzierl, Durham University, UK, Sven Köppel, FIAS, Germany, Michael Bader, TUM, Germany, HDF Guest Bloggers ExaHyPE develops a solver engine for hyperbolic differential equations solved on adaptive Cartesian meshes. It supports various HDF5 output formats. Exascale computing is expected to allow scientists and engineers to simulate, and ultimately understand, wave phenomena with unprecedented accuracy over unprecedented time spans. To harvest the power of exascale machines, well-suited software however has to become available. ExaHyPE is a H2020 project writing a PDE solver engine—similar to a 3D computer game engine—that will allow groups with a decent CSE expertise to write their own solver for hyperbolic equation systems within a year. The resulting solver will scale to exascale. This is made possible by the unique...

Scot Martin, Harvard University, HDF Guest Blogger HDF5 storage is really interesting. To me, its format has no fixed structure, but instead is based on introspection and discovery. Seems great to me; Mathematica has its origins first in artificial intelligence, so we ought to be able to do something here.  Approaching twenty-two years with Mathematica and almost a “Hello, World!” ability in C, I decided to jump right in. Enter The HDF Group's P/Invoke for my salvation. Here’s how we make use of it in Mathematica: LoadNETAssembly["HDF.PInvoke.dll"] Bang! Ready to go in Mathematica. Here’s a proof of concept for how it works: Module[ (* The three symbols should have initial values so that there is *) (* memory allocation when Mathematica interfaces with P/Invoke. *) {major=0,minor=0,revision=0,return}, CompoundExpression[ (* access...

Christian Hoene, Symonics GmbH; and Piotr Majdak, Acoustics Research Institute; HDF Guest Bloggers Spatial audio - 3D sound.  Back in the ‘70’s, “dummy head” microphones were used to create spatial audio recordings. With headphones, one was able to listen to those recordings and marvel at the impressive spatial distribution of sounds – just like in real life. [caption id="attachment_11132" align="aligncenter" width="624"] Displays the difference between listening to a real source and listening to realistic virtual sounds via headphones[/caption] Nowadays, we have a much better understanding of the human binaural perception and we can even simulate spatial audio signals with the help of computers.  Indeed, a modern virtual reality (VR) headset such as the Oculus Rift or Samsung Gear utilizes 3D audio to allow...